The present invention relates to a small solid state laser/amplifier system built on a single metal substrate.
Tatsuno et al. explain in U.S. Pat. No. 5,377,212 that the refractive index of laser crystal media and, therefore, the retardation and wavelength selection changes with temperature. It is disclosed that retardation has been controlled by using a Peltier cooler to control the temperature of a nonlinear crystal against a given crystal length. A slant in the end face of a nonlinear crystal is shown to change the thickness and therefore the retardation depending on the route of passage of the fundamental wave.
Martin in U.S. Pat. No. 5,008,895 shows a flat metal one-piece package with a lid and an attached thermoelectric cooler. Mooradian discloses in U.S. Pat. No. 5,256,164 a solid state laser in which the gain medium is tuned by several temperature regulating elements to select a single wavelength. Dixon disclosed in U.S. Pat. No. 4,847,851 the use of reflective and anti-reflective coatings on laser media. A single heat sink is used to mount all the laser components in thermal contact with a single thermoelectric cooler. Okazaki discloses in U.S. Pat. No. 5,497,387 a wedge shaped etalon fixed in position on a thermoelectric cooler which sets the resonator mode at the temperature of maximum lasing efficiency. This is taught to prevent noise due to mode competition.
None of the prior art disclose separate thermoelectric coolers for each laser crystal medium for independent temperature regulation of each crystal. A mobile etalon is not disclosed together with all the laser media including the pumping lasers to be mounted on a single metal substrate. The problem has been that not all of the various laser media can operate at their optimum efficiency temperatures.
So, there remains a need to provide a solid state laser/amplifier system that is efficient to mass produce with superior long-term reliability such that the various laser media are held at their respective temperatures of maximum lasing efficiency. There is also a need to provide a system which, when operating in the amplification mode, is capable of delivering greater output power with less noise.